/*
 * Copyright 2009-2014 Tensosoft.
 *  
 * Licensed under the Tensosoft Opensource License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.tensosoft.com/eula.html
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.tansuosoft.discoverx.app.imgcode;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.URI;
import java.nio.charset.Charset;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.Callable;

import javax.imageio.ImageIO;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.ResultPoint;
import com.google.zxing.client.result.ParsedResult;
import com.google.zxing.client.result.ResultParser;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.multi.GenericMultipleBarcodeReader;

/**
 * One of a pool of threads which pulls images off the Inputs queue and decodes them in parallel.
 * 
 * @see CommandLineRunner
 */
final class DecodeWorker implements Callable<Integer> {

	private final Config config;
	private final Queue<String> inputs;

	DecodeWorker(Config config, Queue<String> inputs) {
		this.config = config;
		this.inputs = inputs;
	}

	@Override
	public Integer call() throws IOException {
		int successful = 0;
		String input;
		while ((input = inputs.poll()) != null) {
			File inputFile = new File(input);
			if (inputFile.exists()) {
				if (config.isMulti()) {
					Result[] results = decodeMulti(inputFile.toURI(), config.getHints());
					if (results != null) {
						successful++;
						if (config.isDumpResults()) {
							dumpResultMulti(inputFile, results);
						}
					}
				} else {
					Result result = decode(inputFile.toURI(), config.getHints());
					if (result != null) {
						successful++;
						if (config.isDumpResults()) {
							dumpResult(inputFile, result);
						}
					}
				}
			} else {
				if (decode(URI.create(input), config.getHints()) != null) {
					successful++;
				}
			}
		}
		return successful;
	}

	private static void dumpResult(File input, Result result) throws IOException {
		String name = input.getCanonicalPath();
		int pos = name.lastIndexOf('.');
		if (pos > 0) {
			name = name.substring(0, pos);
		}
		File dump = new File(name + ".txt");
		writeStringToFile(result.getText(), dump);
	}

	private static void dumpResultMulti(File input, Result[] results) throws IOException {
		String name = input.getCanonicalPath();
		int pos = name.lastIndexOf('.');
		if (pos > 0) {
			name = name.substring(0, pos);
		}
		File dump = new File(name + ".txt");
		writeResultsToFile(results, dump);
	}

	private static void writeStringToFile(String value, File file) throws IOException {
		Writer out = new OutputStreamWriter(new FileOutputStream(file), Charset.forName("UTF8"));
		try {
			out.write(value);
		} finally {
			out.close();
		}
	}

	private static void writeResultsToFile(Result[] results, File file) throws IOException {
		String newline = System.getProperty("line.separator");
		Writer out = new OutputStreamWriter(new FileOutputStream(file), Charset.forName("UTF8"));
		try {
			for (Result result : results) {
				out.write(result.getText());
				out.write(newline);
			}
		} finally {
			out.close();
		}
	}

	private Result decode(URI uri, Map<DecodeHintType, ?> hints) throws IOException {
		BufferedImage image = ImageReader.readImage(uri);
		try {
			LuminanceSource source;
			if (config.getCrop() == null) {
				source = new BufferedImageLuminanceSource(image);
			} else {
				int[] crop = config.getCrop();
				source = new BufferedImageLuminanceSource(image, crop[0], crop[1], crop[2], crop[3]);
			}
			BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
			if (config.isDumpBlackPoint()) {
				dumpBlackPoint(uri, image, bitmap);
			}
			Result result = new MultiFormatReader().decode(bitmap, hints);
			if (config.isBrief()) {
				System.out.println(uri.toString() + ": Success");
			} else {
				ParsedResult parsedResult = ResultParser.parseResult(result);
				System.out.println(uri.toString() + " (format: " + result.getBarcodeFormat() + ", type: " + parsedResult.getType() + "):\nRaw result:\n" + result.getText() + "\nParsed result:\n" + parsedResult.getDisplayResult());

				System.out.println("Found " + result.getResultPoints().length + " result points.");
				for (int i = 0; i < result.getResultPoints().length; i++) {
					ResultPoint rp = result.getResultPoints()[i];
					if (rp != null) {
						System.out.println("  Point " + i + ": (" + rp.getX() + ',' + rp.getY() + ')');
					}
				}
			}

			return result;
		} catch (NotFoundException ignored) {
			System.out.println(uri.toString() + ": No barcode found");
			return null;
		}
	}

	private Result[] decodeMulti(URI uri, Map<DecodeHintType, ?> hints) throws IOException {
		BufferedImage image = ImageReader.readImage(uri);
		try {
			LuminanceSource source;
			if (config.getCrop() == null) {
				source = new BufferedImageLuminanceSource(image);
			} else {
				int[] crop = config.getCrop();
				source = new BufferedImageLuminanceSource(image, crop[0], crop[1], crop[2], crop[3]);
			}
			BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
			if (config.isDumpBlackPoint()) {
				dumpBlackPoint(uri, image, bitmap);
			}

			MultiFormatReader multiFormatReader = new MultiFormatReader();
			GenericMultipleBarcodeReader reader = new GenericMultipleBarcodeReader(multiFormatReader);
			Result[] results = reader.decodeMultiple(bitmap, hints);

			if (config.isBrief()) {
				System.out.println(uri.toString() + ": Success");
			} else {
				for (Result result : results) {
					ParsedResult parsedResult = ResultParser.parseResult(result);
					System.out.println(uri.toString() + " (format: " + result.getBarcodeFormat() + ", type: " + parsedResult.getType() + "):\nRaw result:\n" + result.getText() + "\nParsed result:\n" + parsedResult.getDisplayResult());
					System.out.println("Found " + result.getResultPoints().length + " result points.");
					for (int i = 0; i < result.getResultPoints().length; i++) {
						ResultPoint rp = result.getResultPoints()[i];
						System.out.println("  Point " + i + ": (" + rp.getX() + ',' + rp.getY() + ')');
					}
				}
			}
			return results;
		} catch (NotFoundException ignored) {
			System.out.println(uri.toString() + ": No barcode found");
			return null;
		}
	}

	/**
	 * Writes out a single PNG which is three times the width of the input image, containing from left to right: the original image, the row sampling monochrome version, and the 2D sampling monochrome
	 * version.
	 */
	private static void dumpBlackPoint(URI uri, BufferedImage image, BinaryBitmap bitmap) {
		// TODO: Update to compare different Binarizer implementations.
		String inputName = uri.getPath();
		if (inputName.contains(".mono.png")) { return; }

		int width = bitmap.getWidth();
		int height = bitmap.getHeight();
		int stride = width * 3;
		int[] pixels = new int[stride * height];

		// The original image
		int[] argb = new int[width];
		for (int y = 0; y < height; y++) {
			image.getRGB(0, y, width, 1, argb, 0, width);
			System.arraycopy(argb, 0, pixels, y * stride, width);
		}

		// Row sampling
		BitArray row = new BitArray(width);
		for (int y = 0; y < height; y++) {
			try {
				row = bitmap.getBlackRow(y, row);
			} catch (NotFoundException nfe) {
				// If fetching the row failed, draw a red line and keep going.
				int offset = y * stride + width;
				for (int x = 0; x < width; x++) {
					pixels[offset + x] = 0xffff0000;
				}
				continue;
			}

			int offset = y * stride + width;
			for (int x = 0; x < width; x++) {
				if (row.get(x)) {
					pixels[offset + x] = 0xff000000;
				} else {
					pixels[offset + x] = 0xffffffff;
				}
			}
		}

		// 2D sampling
		try {
			for (int y = 0; y < height; y++) {
				BitMatrix matrix = bitmap.getBlackMatrix();
				int offset = y * stride + width * 2;
				for (int x = 0; x < width; x++) {
					if (matrix.get(x, y)) {
						pixels[offset + x] = 0xff000000;
					} else {
						pixels[offset + x] = 0xffffffff;
					}
				}
			}
		} catch (NotFoundException ignored) {
			// continue
		}

		writeResultImage(stride, height, pixels, uri, inputName, ".mono.png");
	}

	private static void writeResultImage(int stride, int height, int[] pixels, URI uri, String inputName, String suffix) {
		// Write the result
		BufferedImage result = new BufferedImage(stride, height, BufferedImage.TYPE_INT_ARGB);
		result.setRGB(0, 0, stride, height, pixels, 0, stride);

		// Use the current working directory for URLs
		String resultName = inputName;
		if ("http".equals(uri.getScheme())) {
			int pos = resultName.lastIndexOf('/');
			if (pos > 0) {
				resultName = '.' + resultName.substring(pos);
			}
		}
		int pos = resultName.lastIndexOf('.');
		if (pos > 0) {
			resultName = resultName.substring(0, pos);
		}
		resultName += suffix;
		OutputStream outStream = null;
		try {
			outStream = new FileOutputStream(resultName);
			if (!ImageIO.write(result, "png", outStream)) {
				System.err.println("Could not encode an image to " + resultName);
			}
		} catch (FileNotFoundException ignored) {
			System.err.println("Could not create " + resultName);
		} catch (IOException ignored) {
			System.err.println("Could not write to " + resultName);
		} finally {
			try {
				if (outStream != null) {
					outStream.close();
				}
			} catch (IOException ioe) {
				// continue
			}
		}
	}

}

